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1.
Cell ; 186(11): 2313-2328.e15, 2023 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-37146612

RESUMO

Hybrid potato breeding will transform the crop from a clonally propagated tetraploid to a seed-reproducing diploid. Historical accumulation of deleterious mutations in potato genomes has hindered the development of elite inbred lines and hybrids. Utilizing a whole-genome phylogeny of 92 Solanaceae and its sister clade species, we employ an evolutionary strategy to identify deleterious mutations. The deep phylogeny reveals the genome-wide landscape of highly constrained sites, comprising ∼2.4% of the genome. Based on a diploid potato diversity panel, we infer 367,499 deleterious variants, of which 50% occur at non-coding and 15% at synonymous sites. Counterintuitively, diploid lines with relatively high homozygous deleterious burden can be better starting material for inbred-line development, despite showing less vigorous growth. Inclusion of inferred deleterious mutations increases genomic-prediction accuracy for yield by 24.7%. Our study generates insights into the genome-wide incidence and properties of deleterious mutations and their far-reaching consequences for breeding.


Assuntos
Melhoramento Vegetal , Solanum tuberosum , Diploide , Mutação , Filogenia , Solanum tuberosum/genética
2.
Proc Natl Acad Sci U S A ; 121(26): e2319811121, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38889146

RESUMO

Rational design of plant cis-regulatory DNA sequences without expert intervention or prior domain knowledge is still a daunting task. Here, we developed PhytoExpr, a deep learning framework capable of predicting both mRNA abundance and plant species using the proximal regulatory sequence as the sole input. PhytoExpr was trained over 17 species representative of major clades of the plant kingdom to enhance its generalizability. Via input perturbation, quantitative functional annotation of the input sequence was achieved at single-nucleotide resolution, revealing an abundance of predicted high-impact nucleotides in conserved noncoding sequences and transcription factor binding sites. Evaluation of maize HapMap3 single-nucleotide polymorphisms (SNPs) by PhytoExpr demonstrates an enrichment of predicted high-impact SNPs in cis-eQTL. Additionally, we provided two algorithms that harnessed the power of PhytoExpr in designing functional cis-regulatory variants, and de novo creation of species-specific cis-regulatory sequences through in silico evolution of random DNA sequences. Our model represents a general and robust approach for functional variant discovery in population genetics and rational design of regulatory sequences for genome editing and synthetic biology.


Assuntos
Polimorfismo de Nucleotídeo Único , Sequências Reguladoras de Ácido Nucleico , Zea mays , Sequências Reguladoras de Ácido Nucleico/genética , Zea mays/genética , Locos de Características Quantitativas , Algoritmos , Regulação da Expressão Gênica de Plantas , Aprendizado Profundo , Plantas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Modelos Genéticos , Genes de Plantas , Sítios de Ligação/genética
3.
Blood ; 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38518104

RESUMO

Given the poor outcome of refractory and relapsing T-ALL, identifying prognostic markers is still challenging. Using SNP-array analysis, we provide a comprehensive analysis of genomic imbalances in a cohort of 317 newly-diagnosed T-ALL patients including 135 children and 182 adults with respect to clinical and biological features and outcomes. SNP-array results identified at least one somatic genomic imbalance in virtually all T-ALL patients (~96%). Del(9)(p21) (~70%) and UPD(9)p21)/CDKN2A/B (~28%) were the most frequent genomic imbalances. Unexpectedly del(13q14)/RB1/DLEU1 (~14%) was the second more frequent CNV followed by del(6)(q15)/CASP8AP2 (~11%), del(1)(p33)/SIL-TAL1 (~11%), del(12)(p13)ETV6/CDKN1B (~9%), del(18)(p11)/PTPN2 (~9%), del(1)(p36)/RPL22 (~9%), and del(17)(q11)/NF1/SUZ12 (~8%). SNP-array also revealed distinct profiles of genomic imbalances according to age, immunophenotype, and oncogenetic subgroups. In particular, adult T-ALL patients demonstrated a significantly higher incidence of del(1)(p36)/RPL22, and del(13)(q14)/RB1/DLEU1, and lower incidence of del(9)(p21) and UPD(9p21)/CDKN2A/B. We determined a threshold of 15 genomic imbalances to stratify patients into high- and low-risk groups of relapse. Survival analysis also revealed the poor outcome, despite the low number of affected cases, conferred by the presence of chromothripsis (n=6, ~2%), del(16)(p13)/CREBBP (n=15, ~5%) as well as the newly identified recurrent gain at 6q27 involving MLLT4 (n=10, ~3%). Genomic complexity, del(16)(p13)/CREBBP and gain at 6q27 involving MLLT4 maintained their significance in multivariate analysis for survival outcome. Our study thus demonstrated that whole genome analysis of imbalances provides new insights to refine risk stratification in T-ALL.

4.
Blood ; 142(2): 158-171, 2023 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-37023368

RESUMO

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a dismal prognosis related to refractory/relapsing diseases, raising the need for new targeted therapies. Activating mutations of interleukin-7-receptor pathway genes (IL-7Rp) play a proven leukemia-supportive role in T-ALL. JAK inhibitors, such as ruxolitinib, have recently demonstrated preclinical efficacy. However, prediction markers for sensitivity to JAK inhibitors are still lacking. Herein, we show that IL-7R (CD127) expression is more frequent (∼70%) than IL-7Rp mutations in T-ALL (∼30%). We compared the so-called nonexpressers (no IL-7R expression/IL-7Rp mutation), expressers (IL7R expression without IL-7Rp mutation), and mutants (IL-7Rp mutations). Integrative multiomics analysis outlined IL-7R deregulation in virtually all T-ALL subtypes, at the epigenetic level in nonexpressers, genetic level in mutants, and posttranscriptional level in expressers. Ex vivo data using primary-derived xenografts support that IL-7Rp is functional whenever the IL-7R is expressed, regardless of the IL-7Rp mutational status. Consequently, ruxolitinib impaired T-ALL survival in both expressers and mutants. Interestingly, we show that expressers displayed ectopic IL-7R expression and IL-7Rp addiction conferring a deeper sensitivity to ruxolitinib. Conversely, mutants were more sensitive to venetoclax than expressers. Overall, the combination of ruxolitinib and venetoclax resulted in synergistic effects in both groups. We illustrate the clinical relevance of this association by reporting the achievement of complete remission in 2 patients with refractory/relapsed T-ALL. This provides proof of concept for translation of this strategy into clinics as a bridge-to-transplantation therapy. IL7R expression can be used as a biomarker for sensitivity to JAK inhibition, thereby expanding the fraction of patients with T-ALL eligible for ruxolitinib up to nearly ∼70% of T-ALL cases.


Assuntos
Inibidores de Janus Quinases , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Inibidores de Janus Quinases/uso terapêutico , Linfócitos T/patologia
5.
J Physiol ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685758

RESUMO

We investigated the role played by lactate and hydrogen in evoking the exercise pressor reflex (EPR) in decerebrated rats whose hindlimb muscles were either freely perfused or ischaemic. Production of lactate and hydrogen by the contracting hindlimb muscles was manipulated by knocking out the myophosphorylase gene (pygm). In knockout rats (pygm-/-; n = 13) or wild-type rats (pygm+/+; n = 13), the EPR was evoked by isometrically contracting the triceps surae muscles. Blood pressure, tension, blood flow, renal sympathetic nerve activity and blood lactate concentrations were measured. Intramuscular metabolites and pH changes induced by the contractions were quantified by 31P-magnetic resonance spectroscopy (n = 5). In a subset of pygm-/- rats (n = 5), contractions were evoked with prior infusion of lactate (pH 6.0) in an attempt to restore the effect of lactate and hydrogen ions. Contraction of freely perfused muscles increased blood lactate and decreased muscle pH in pygm+/+ rats only. Despite these differences, the reflex pressor and sympathetic responses to freely perfused contraction did not differ between groups (P = 0.992). During ischaemia, contraction increased muscle lactate and hydrogen ion production in pygm+/+ rats (P < 0.0134), whereas it had no effect in pygm-/- rats (P > 0.783). Likewise, ischaemia exaggerated the reflex pressor, and sympathetic responses to contraction in pygm+/+ but not in pygm-/- rats. This exaggeration was restored when a solution of lactate (pH 6.0) was infused prior to the contraction in pygm-/- rats. We conclude that lactate and hydrogen accumulation in contracting myocytes play a key role in evoking the metabolic component of the EPR during ischaemic but not during freely perfused contractions. KEY POINTS: Conflicting results exist about the role played by lactate and hydrogen ions in evoking the exercise pressor reflex. Using CRISP-Cas9, we rendered the myophosphorylase gene non-functional to block the production of lactate and hydrogen ions. The exercise pressor reflex was evoked in decerebrated rats by statically contracting the triceps surae muscles with or without muscle ischaemia. Static contraction elevated the concentration of lactate and hydrogen ions in pygm+/+ but not in pygm-/- rats. Despite these differences, the exercise pressor reflex was not different between groups. Acute muscle ischaemia exaggerated the concentration of lactate and hydrogen ions in pygm+/+ but not in pygm-/- rats. Likewise, acute muscle ischaemia exaggerated the exercise pressor reflex in pygm+/+ but not in pygm-/- rats. We conclude that lactate and hydrogen play a key role in evoking the exercise pressor reflex during ischaemic but not during freely perfused contractions.

6.
J Physiol ; 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38340081

RESUMO

We determined the role played by the transient receptor potential canonical 6 (TRPC6) channel in evoking the mechanical component of the exercise pressor reflex in male decerebrated Sprague-Dawley rats. TRPC6 channels were identified by quadruple-labelled (DiI, TRPC6, neurofilament-200 and peripherin) immunohistochemistry in dorsal root ganglion (DRG) cells innervating the triceps surae muscles (n = 12). The exercise pressor reflex was evoked by statically contracting the triceps surae muscles before and after injection of the TRPC6 antagonist BI-749327 (n = 11; 12 µg kg-1 ) or SAR7334 (n = 11; 7 µg kg-1 ) or the TRPC6 positive modulator C20 (n = 11; 18 µg kg-1 ). Similar experiments were conducted while the muscles were passively stretched (n = 8-12), a manoeuvre that isolated the mechanical component of the reflex. Blood pressure, tension, renal sympathetic nerve activity (RSNA) and blood flow were recorded. Of the DRG cells innervating the triceps surae muscles, 85% stained positive for the TRPC6 antigen, and 45% of those cells co-expressed neurofilament-200. Both TRPC6 antagonists decreased the reflex pressor responses to static contraction (-32 to -42%; P < 0.05) and to passive stretch (-35 to -52%; P < 0.05), whereas C20 increased these responses (55-65%; P < 0.05). In addition, BI-749327 decreased the peak and integrated RSNA responses to both static contraction (-39 to -43%; P < 0.05) and passive stretch (-56 to -62%; P < 0.05), whereas C20 increased the RSNA to passive stretch only. The onset latency of the decrease or increase in RSNA occurred within 2 s of the onset of the manoeuvres (P < 0.05). Collectively, our results show that TRPC6 plays a key role in evoking the mechanical component of the exercise pressor reflex. KEY POINTS: The exercise pressor reflex plays a key role in the sympathetic and haemodynamic responses to exercise. This reflex is composed of two components, namely the mechanoreflex and the metaboreflex. The receptors responsible for evoking the mechanoreflex are poorly documented. A good candidate for this function is the transient receptor potential canonical 6 (TRPC6) channel, which is activated by mechanical stimuli and expressed in dorsal root ganglia of rats. Using two TRPC6 antagonists and one positive modulator, we investigated the role played by TRPC6 in evoking the mechanoreflex in decerebrated rats. Blocking TRPC6 decreased the renal sympathetic and the pressor responses to both contraction and stretch, the latter being a manoeuvre that isolates the mechanoreflex. In contrast, the positive modulator increased the pressor reflex to contraction and stretch, in addition to the sympathetic response to stretch. Our results provide strong support for a role played by the TRPC6 channel in evoking the mechanoreflex.

7.
Crit Care Med ; 52(2): 170-181, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38240504

RESUMO

OBJECTIVES: Cardiac arrests remain a leading cause of death worldwide. Most patients have nonshockable electrocardiographic presentations (asystole/pulseless electrical activity). Despite well-performed basic and advanced cardiopulmonary resuscitation (CPR) interventions, patients with these presentations have always faced unlikely chances of survival. The primary objective was to determine if, in addition to conventional CPR (C-CPR), expeditious application of noninvasive circulation-enhancing adjuncts, and then gradual elevation of head and thorax, would be associated with higher likelihoods of survival following out-of-hospital cardiac arrest (OHCA) with nonshockable presentations. DESIGN: Using a prospective observational study design (ClinicalTrials.gov NCT05588024), patient data from the national registry of emergency medical services (EMS) agencies deploying the CPR-enhancing adjuncts and automated head/thorax-up positioning (AHUP-CPR) were compared with counterpart reference control patient data derived from the two National Institutes of Health clinical trials that closely monitored quality CPR performance. Beyond unadjusted comparisons, propensity score matching and matching of time to EMS-initiated CPR (TCPR) were used to assemble cohorts with corresponding best-fit distributions of the well-established characteristics associated with OHCA outcomes. SETTING: North American 9-1-1 EMS agencies. PATIENTS: Adult nontraumatic OHCA patients receiving 9-1-1 responses. INTERVENTIONS: In addition to C-CPR, study patients received the CPR adjuncts and AHUP (all U.S. Food and Drug Administration-cleared). MEASUREMENTS AND MAIN RESULTS: The median TCPR for both AHUP-CPR and C-CPR groups was 8 minutes. Median time to AHUP initiation was 11 minutes. Combining all patients irrespective of lengthier response intervals, the collective unadjusted likelihood of AHUP-CPR group survival to hospital discharge was 7.4% (28/380) vs. 3.1% (58/1,852) for C-CPR (odds ratio [OR], 2.46 [95% CI, 1.55-3.92]) and, after propensity score matching, 7.6% (27/353) vs. 2.8% (10/353) (OR, 2.84 [95% CI, 1.35-5.96]). Faster AHUP-CPR application markedly amplified odds of survival and neurologically favorable survival. CONCLUSIONS: These findings indicate that, compared with C-CPR, there are strong associations between rapid AHUP-CPR treatment and greater likelihood of patient survival, as well as survival with good neurological function, in cases of nonshockable OHCA.


Assuntos
Reanimação Cardiopulmonar , Serviços Médicos de Emergência , Parada Cardíaca Extra-Hospitalar , Adulto , Humanos , Cardioversão Elétrica , Parada Cardíaca Extra-Hospitalar/terapia , Tórax
8.
Eur J Nucl Med Mol Imaging ; 51(4): 1185-1193, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38038755

RESUMO

PURPOSE: To assess early tumor response with quantitated SPECT/CT and to correlate it with clinical outcome in metastatic castration-resistant prostate cancer (mCRPC) patients treated with 177Lutetium-PSMA I&T therapy. METHODS: Single-center, observational study, part of the prospective Swiss national cancer registry study investigating the safety and efficacy of [177Lu]Lu-PSMA I&T (EKNZ: 2021-01271) in mCRPC patients treated with at least two cycles of [177Lu]Lu-PSMA I&T 6-weekly. After the first and second cycle quantitated SPECT/CT (Symbia Intevo, Siemens) was acquired 48 h after injection (three fields of view from head to thigh, 5 s/frame) and reconstructed using xQuant® (48i, 1 s, 10-mm Gauss). Image analysis: The PSMA-positive total tumor volumes (TTV) were semi-automatically delineated using a SUV threshold of 3 with MIMencore® (version 7.1.3, Medical Image Merge Software Inc.). Changes in TTV, highest tumor SUVmax, and total tumor SUVmean between cycles 1 and 2 were calculated and grouped into a) stable or decrease and b) increase. Serum PSA levels were assessed at each therapy cycle and at follow-up until progression or death. Changes in TTV, PSA, SUVmax, and SUVmean were correlated with PSA-progression-free survival (PSA-PFS) and the overall survival (OS) using the Kaplan-Meier methodology (log-rank test). RESULTS: Between 07/2020 and 04/2022, 111 patients were screened and 73 finally included in the data analysis. The median follow-up was 8.9 months (range 1.4-26.6 months). Stable or decreased TTV at cycle 2 was associated with longer OS (hazard ratio (HR) 0.28, 95% confidence interval (CI) 0.09-0.86, p < 0.01). Similar, stable, or decreased PSA was associated with longer OS (HR 0.21; CI 0.07-0.62, p < 0.01) and PSA-PFS (HR 0.34; 95% CI 0.16-0.72, p < 0.01). Combining TTV and PSA will result in an augmented prognostic value for OS (HR 0.09; CI 0.01-0.63; p < 0.01) and for PSA-PFS (HR 0.11; CI 0.02-0.68; p < 0.01). A reduction of SUVmax or SUVmean was not prognostically relevant, neither for OS (p 0.88 and 0.7) nor for PSA-PFS (p 0.73 and 0.62, respectively). CONCLUSION: Six weeks after initiating [177Lu]Lu-PSMA I&T, TTV and serum PSA appear to be good prognosticators for OS. Combined together, TTV + PSA change demonstrates augmented prognostic value and can better predict PSA-PFS. Larger studies using TTV change prospectively as an early-response biomarker are warranted for implementing management change towards a more personalized clinical practice.


Assuntos
Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração , Ureia/análogos & derivados , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/diagnóstico por imagem , Neoplasias de Próstata Resistentes à Castração/radioterapia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Suíça , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Resultado do Tratamento , Compostos Heterocíclicos com 1 Anel/uso terapêutico , Lutécio/uso terapêutico , Dipeptídeos/uso terapêutico , Estudos Retrospectivos
9.
Eur J Nucl Med Mol Imaging ; 51(8): 2428-2441, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38528164

RESUMO

PURPOSE: To evaluate the dosimetry and pharmacokinetics of the novel radiolabelled somatostatin receptor antagonist [177Lu]Lu-satoreotide tetraxetan in patients with advanced neuroendocrine tumours (NETs). METHODS: This study was part of a phase I/II trial of [177Lu]Lu-satoreotide tetraxetan, administered at a median cumulative activity of 13.0 GBq over three planned cycles (median activity/cycle: 4.5 GBq), in 40 patients with progressive NETs. Organ absorbed doses were monitored at each cycle using patient-specific dosimetry; the cumulative absorbed-dose limits were set at 23.0 Gy for the kidneys and 1.5 Gy for bone marrow. Absorbed dose coefficients (ADCs) were calculated using both patient-specific and model-based dosimetry for some patients. RESULTS: In all evaluated organs, maximum [177Lu]Lu-satoreotide tetraxetan uptake was observed at the first imaging timepoint (4 h after injection), followed by an exponential decrease. Kidneys were the main route of elimination, with a cumulative excretion of 57-66% within 48 h following the first treatment cycle. At the first treatment cycle, [177Lu]Lu-satoreotide tetraxetan showed a median terminal blood half-life of 127 h and median ADCs of [177Lu]Lu-satoreotide tetraxetan were 5.0 Gy/GBq in tumours, 0.1 Gy/GBq in the bone marrow, 0.9 Gy/GBq in kidneys, 0.2 Gy/GBq in the liver and 0.8 Gy/GBq in the spleen. Using image-based dosimetry, the bone marrow and kidneys received median cumulative absorbed doses of 1.1 and 10.8 Gy, respectively, after three cycles. CONCLUSION: [177Lu]Lu-satoreotide tetraxetan showed a favourable dosimetry profile, with high and prolonged tumour uptake, supporting its acceptable safety profile and promising efficacy. TRIAL REGISTRATION: NCT02592707. Registered October 30, 2015.


Assuntos
Tumores Neuroendócrinos , Humanos , Tumores Neuroendócrinos/radioterapia , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/metabolismo , Masculino , Pessoa de Meia-Idade , Feminino , Idoso , Adulto , Radiometria , Lutécio/farmacocinética , Distribuição Tecidual , Somatostatina/análogos & derivados , Somatostatina/farmacocinética , Progressão da Doença , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/uso terapêutico , Idoso de 80 Anos ou mais , Octreotida/análogos & derivados , Octreotida/farmacocinética , Octreotida/uso terapêutico , Radioisótopos
10.
PLoS Genet ; 17(10): e1009568, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34606492

RESUMO

Genomic prediction typically relies on associations between single-site polymorphisms and traits of interest. This representation of genomic variability has been successful for predicting many complex traits. However, it usually cannot capture the combination of alleles in haplotypes and it has generated little insight about the biological function of polymorphisms. Here we present a novel and cost-effective method for imputing cis haplotype associated RNA expression (HARE), studied their transferability across tissues, and evaluated genomic prediction models within and across populations. HARE focuses on tightly linked cis acting causal variants in the immediate vicinity of the gene, while excluding trans effects from diffusion and metabolism. Therefore, HARE estimates were more transferrable across different tissues and populations compared to measured transcript expression. We also showed that HARE estimates captured one-third of the variation in gene expression. HARE estimates were used in genomic prediction models evaluated within and across two diverse maize panels-a diverse association panel (Goodman Association panel) and a large half-sib panel (Nested Association Mapping panel)-for predicting 26 complex traits. HARE resulted in up to 15% higher prediction accuracy than control approaches that preserved haplotype structure, suggesting that HARE carried functional information in addition to information about haplotype structure. The largest increase was observed when the model was trained in the Nested Association Mapping panel and tested in the Goodman Association panel. Additionally, HARE yielded higher within-population prediction accuracy as compared to measured expression values. The accuracy achieved by measured expression was variable across tissues, whereas accuracy by HARE was more stable across tissues. Therefore, imputing RNA expression of genes by haplotype is stable, cost-effective, and transferable across populations.


Assuntos
Haplótipos/genética , Locos de Características Quantitativas/genética , RNA/genética , Zea mays/genética , Alelos , Mapeamento Cromossômico/métodos , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Genótipo , Desequilíbrio de Ligação/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
11.
Vet Radiol Ultrasound ; 65(3): 255-263, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38419292

RESUMO

The objective of this retrospective clinical study was to determine if airway or thoracic cavity measurements in pugs, particularly the left cranial lung lobe, were significantly different from brachycephalic and mesocephalic control. Thoracic computed tomographic studies of 10 pugs, French bulldogs (FB), and Jack Russell Terriers (JRT) were analyzed. Thoracic height: width ratio (H:W), cross-sectional areas of the left mainstem bronchus (CSA LMB), left cranial lung lobe bronchus (CSA LCrBr), left caudal lung lobe bronchus (CSA LCauBr), CSA LCrBr relative to length (CSA LCrBr/length) and CSA LCauBr/length were measured and adjusted to body weight (/kg). CSA LMB/kg, CSA LCauBr/length/kg, and CSA LCrBr/length /kg were smaller in pugs and FB compared with JRT (P < .05), but no differences were found between pugs and FB. Cross-sectional areas of left cranial lung lobe bronchus /kg and CSA LCauBr/kg were smaller in pugs than JRT (P < .05), but no differences were found between pugs and FB or FB and JRT. No difference was found in thoracic H:W between any breeds. This demonstrated that pugs and FB had significantly narrower bronchi CSA/lengths ratios compared with JRT, but this was not limited to the LCBr. Airway measurements were not significantly different between brachycephalic breeds; therefore, the pugs' predisposition to left cranial lung lobe torsion cannot be solely explained by narrower lower airways.


Assuntos
Doenças do Cão , Tomografia Computadorizada por Raios X , Animais , Cães/anatomia & histologia , Doenças do Cão/diagnóstico por imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/veterinária , Masculino , Feminino , Pulmão/diagnóstico por imagem , Cavidade Torácica/diagnóstico por imagem , Anormalidade Torcional/veterinária , Anormalidade Torcional/diagnóstico por imagem , Brônquios/diagnóstico por imagem , Brônquios/anatomia & histologia , Pneumopatias/veterinária , Pneumopatias/diagnóstico por imagem
12.
J Physiol ; 601(23): 5241-5256, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37878364

RESUMO

The role played by the transient receptor potential vanilloid 1 (TRPV1) channel on the thin fibre afferents evoking the exercise pressor reflex is controversial. To shed light on this controversy, we compared the exercise pressor reflex between newly developed TRPV1+/+ , TRPV1+/- and TRPV1-/- rats. Carotid arterial injection of capsaicin (0.5 µg), evoked significant pressor responses in TRPV1+/+ and TRPV1+/- rats, but not in TRPV1-/- rats. In acutely isolated dorsal root ganglion neurons innervating the gastrocnemius muscles, capsaicin evoked inward currents in neurons isolated from TRPV1+/+ and TRPV1+/- rats but not in neurons isolated from TRPV1-/- rats. The reflex was evoked by stimulating the tibial nerve in decerebrated rats whose femoral artery was either freely perfused or occluded. We found no difference between the reflex in the three groups of rats regardless of the patency of the femoral artery. For example, the peak pressor responses to contraction in TRPV1+/+ , TRPV1+/- and TRPV1-/- rats with patent femoral arteries averaged 17.1 ± 7.2, 18.9 ± 12.4 and 18.4 ± 8.6 mmHg, respectively. Stimulation of the tibial nerve after paralysis with pancuronium had no effect on arterial pressure, findings which indicated that the pressor responses to contraction were not caused by electrical stimulation of afferent tibial nerve axons. We also found that expression levels of acid-sensing ion channel 1 and endoperoxide 4 receptor in the L4 and 5 dorsal root ganglia were not upregulated in the TRPV1-/- rats. We conclude that TRPV1 is not needed to evoke the exercise pressor reflex in rats whose contracting muscles have either a patent or an occluded arterial blood supply. KEY POINTS: A reflex arising in contracting skeletal muscle contributes to the increases in arterial blood pressure, cardiac output and breathing evoked by exercise. The sensory arm of the reflex comprises both mechanoreceptors and metaboreceptors, of which the latter signals that blood flow to exercising muscle is not meeting its metabolic demand. The nature of the channel on the metaboreceptor sensing a mismatch between supply and demand is controversial; some believe that it is the transient receptor potential vanilloid 1 (TRPV1) channel. Using genetically engineered rats in which the TRPV1 channel is rendered non-functional, we have shown that it is not needed to evoke the metaboreflex.


Assuntos
Capsaicina , Canais de Potencial de Receptor Transitório , Animais , Ratos , Pressão Sanguínea , Capsaicina/farmacologia , Artéria Femoral/metabolismo , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Ratos Sprague-Dawley , Reflexo/fisiologia , Canais de Potencial de Receptor Transitório/metabolismo
13.
J Am Chem Soc ; 145(14): 7992-8000, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-36995316

RESUMO

Catalytic C-H borylation is an attractive method for the conversion of the most abundant hydrocarbon, methane (CH4), to a mild nucleophilic building block. However, existing CH4 borylation catalysts often suffer from low turnover numbers and conversions, which is hypothesized to result from inactive metal hydride agglomerates. Herein we report that the heterogenization of a bisphosphine molecular precatalyst, [(dmpe)Ir(cod)CH3], onto amorphous silica dramatically enhances its performance, yielding a catalyst that is 12-times more efficient than the current standard for CH4 borylation. The catalyst affords over 2000 turnovers at 150 °C in 16 h with a selectivity of 91.5% for mono- vs diborylation. Higher catalyst loadings improve yield and selectivity for the monoborylated product (H3CBpin) with 82.8% yield and >99% selectivity being achieved with 1255 turnovers. X-ray absorption and dynamic nuclear polarization-enhanced solid-state NMR spectroscopic studies identify the supported precatalyst as an IrI species, and indicate that upon completion of catalysis, multinuclear Ir polyhydrides are not formed. This is consistent with the hypothesis that immobilization of the organometallic Ir species on a surface prevents bimolecular decomposition pathways. Immobilization of the homogeneous IrI fragment onto amorphous silica represents a unique and simple strategy to improve the TON and longevity of a CH4 borylation catalyst.

14.
Mol Cancer ; 22(1): 12, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36650499

RESUMO

The acquisition of genetic abnormalities engendering oncogene dysregulation underpins cancer development. Certain proto-oncogenes possess several dysregulation mechanisms, yet how each mechanism impacts clinical outcome is unclear. Using T-cell acute lymphoblastic leukemia (T-ALL) as an example, we show that patients harboring 5'super-enhancer (5'SE) mutations of the TAL1 oncogene identifies a specific patient subgroup with poor prognosis irrespective of the level of oncogene dysregulation. Remarkably, the MYB dependent oncogenic 5'SE can be targeted using Mebendazole to induce MYB protein degradation and T-ALL cell death. Of note Mebendazole treatment demonstrated efficacy in vivo in T-ALL preclinical models. Our work provides proof of concept that within a specific oncogene driven cancer, the mechanism of oncogene dysregulation rather than the oncogene itself can identify clinically distinct patient subgroups and pave the way for future super-enhancer targeting therapy.


Assuntos
Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteína 1 de Leucemia Linfocítica Aguda de Células T/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Mebendazol
15.
Plant Physiol ; 189(4): 2144-2158, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35512195

RESUMO

The cuticle, a hydrophobic layer of cutin and waxes synthesized by plant epidermal cells, is the major barrier to water loss when stomata are closed. Dissecting the genetic architecture of natural variation for maize (Zea mays L.) leaf cuticular conductance (gc) is important for identifying genes relevant to improving crop productivity in drought-prone environments. To this end, we performed an integrated genome- and transcriptome-wide association studies (GWAS and TWAS) to identify candidate genes putatively regulating variation in leaf gc. Of the 22 plausible candidate genes identified, 4 were predicted to be involved in cuticle precursor biosynthesis and export, 2 in cell wall modification, 9 in intracellular membrane trafficking, and 7 in the regulation of cuticle development. A gene encoding an INCREASED SALT TOLERANCE1-LIKE1 (ISTL1) protein putatively involved in intracellular protein and membrane trafficking was identified in GWAS and TWAS as the strongest candidate causal gene. A set of maize nested near-isogenic lines that harbor the ISTL1 genomic region from eight donor parents were evaluated for gc, confirming the association between gc and ISTL1 in a haplotype-based association analysis. The findings of this study provide insights into the role of regulatory variation in the development of the maize leaf cuticle and will ultimately assist breeders to develop drought-tolerant maize for target environments.


Assuntos
Estudo de Associação Genômica Ampla , Zea mays , Folhas de Planta/metabolismo , Transcriptoma , Ceras/metabolismo , Zea mays/metabolismo
16.
Blood ; 138(19): 1855-1869, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34125178

RESUMO

T-cell acute lymphoblastic leukemia (T-ALL) is a group of aggressive hematological cancers with dismal outcomes that are in need of new therapeutic options. Polycomb repressor complex 2 (PRC2) loss-of-function alterations were reported in pediatric T-ALL, yet their clinical relevance and functional consequences remain elusive. Here, we extensively analyzed PRC2 alterations in a large series of 218 adult T-ALL patients. We found that PRC2 genetic lesions are frequent events in T-ALL and are not restricted to early thymic precursor ALL. PRC2 loss of function associates with activating mutations of the IL7R/JAK/STAT pathway. PRC2-altered T-ALL patients respond poorly to prednisone and have low bone marrow blast clearance and persistent minimal residual disease. Furthermore, we identified that PRC2 loss of function profoundly reshapes the genetic and epigenetic landscapes, leading to the reactivation of stem cell programs that cooperate with bromodomain and extraterminal (BET) proteins to sustain T-ALL. This study identifies BET proteins as key mediators of the PRC2 loss of function-induced remodeling. Our data have uncovered a targetable vulnerability to BET inhibition that can be exploited to treat PRC2-altered T-ALL patients.


Assuntos
Regulação Leucêmica da Expressão Gênica , Mutação com Perda de Função , Complexo Repressor Polycomb 2/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Animais , Antineoplásicos Hormonais/uso terapêutico , Linhagem Celular Tumoral , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Mutação com Perda de Função/efeitos dos fármacos , Masculino , Camundongos SCID , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Prednisona/uso terapêutico , Fatores de Transcrição/antagonistas & inibidores , Células Tumorais Cultivadas , Adulto Jovem
17.
Eur J Nucl Med Mol Imaging ; 51(1): 183-195, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37721581

RESUMO

PURPOSE: We present the results of an open-label, phase I/II study evaluating the safety and efficacy of the novel somatostatin receptor (SSTR) antagonist [177Lu]Lu-satoreotide tetraxetan in 40 patients with previously treated, progressive neuroendocrine tumours (NETs), in which dosimetry was used to guide maximum administered activity. METHODS: This study was conducted in two parts. Part A consisted of 15 patients who completed three cycles of [177Lu]Lu-satoreotide tetraxetan at a fixed administered activity and peptide amount per cycle (4.5 GBq/300 µg). Part B, which included 25 patients who received one to five cycles of [177Lu]Lu-satoreotide tetraxetan, evaluated different administered activities (4.5 or 6.0 GBq/cycle) and peptide amounts (300, 700, or 1300 µg/cycle), limited to a cumulative absorbed radiation dose of 23 Gy to the kidneys and 1.5 Gy to the bone marrow. RESULTS: Median cumulative administered activity of [177Lu]Lu-satoreotide tetraxetan was 13.0 GBq over three cycles (13.1 GBq in part A and 12.9 GBq in part B). Overall, 17 (42.5%) patients experienced grade ≥ 3 treatment­related adverse events; the most common were lymphopenia, thrombocytopenia, and neutropenia. No grade 3/4 nephrotoxicity was observed. Two patients developed myeloid neoplasms considered treatment related by the investigator. Disease control rate for part A and part B was 94.7% (95% confidence interval [CI]: 82.3-99.4), and overall response rate was 21.1% (95% CI: 9.6-37.3). CONCLUSION: [177Lu]Lu-satoreotide tetraxetan, administered at a median cumulative activity of 13.0 GBq over three cycles, has an acceptable safety profile with a promising clinical response in patients with progressive, SSTR-positive NETs. A 5-year long-term follow-up study is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02592707. Registered October 30, 2015.


Assuntos
Tumores Neuroendócrinos , Compostos Organometálicos , Humanos , Tumores Neuroendócrinos/radioterapia , Tumores Neuroendócrinos/tratamento farmacológico , Receptores de Somatostatina , Octreotida/efeitos adversos , Seguimentos , Compostos Organometálicos/efeitos adversos
18.
Exp Physiol ; 107(4): 312-325, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35137992

RESUMO

NEW FINDINGS: What is the central question of this study? Does the work done above critical power (W') or muscle activation determine the degree of peripheral fatigue induced by cycling time trials performed in the severe-intensity domain? What is the main finding and its importance? Peripheral fatigue increased when power output and muscle activation increased, whereas W' did not change between the time trials. Therefore, no relationship was found between W' and exercise-induced peripheral fatigue such as previously postulated in the literature. In contrast, we found a significant association between EMG amplitude during exercise and exercise-induced reduction in the potentiated quadriceps twitch, suggesting that muscle activation plays a key role in determining peripheral fatigue during severe-intensity exercise. ABSTRACT: In order to determine the relationship between peripheral fatigue, muscle activation and the total work done above critical power (W'), 10 men and four women performed, on separated days, self-paced cycling time trials of 3, 6, 10 and 15 min. Exercise-induced quadriceps fatigue was quantified using pre- to postexercise (15 s to 15 min recovery) changes in maximal voluntary contraction (MVC) peak force, voluntary activation and potentiated twitch force (QT). Voluntary activation was measured using the interpolated twitch technique, and QT was evoked by electrical stimulations of the femoral nerve. Quadriceps muscle activation was determined using the root mean square of surface EMG of vastus lateralis (VLRMS ), vastus medialis (VMRMS ) and rectus femoris (RFRMS ). Critical power and W' were calculated from the power-duration relationship from the four time trials. Mean power output and mean VLRMS , VMRMS and RFRMS were greater during shorter compared with longer exercise periods (P < 0.05), whereas no significant between-trial change in W' was found. The magnitude of exercise-induced reductions in QT increased with the increase in power output (P < 0.001) and was associated with mean VLRMS, VMRMS and RFRMS (P < 0.001, r2  > 0.369) but not W' (P > 0.150, r2  < 0.044). Reduction in voluntary activation tended (P = 0.067) to be more pronounced with the lengthening in time trial duration, whereas no significant between-trial changes in MVC peak force were found. Our data suggest that peripheral fatigue is not related to the amount of work done above the critical power but rather to the level of muscle activation during exercise in the severe-intensity domain.


Assuntos
Exercício Físico , Fadiga Muscular , Eletromiografia , Exercício Físico/fisiologia , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Músculo Quadríceps/fisiologia
19.
PLoS Comput Biol ; 17(2): e1008138, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33577553

RESUMO

Skilled behavior often displays signatures of Bayesian inference. In order for the brain to implement the required computations, neuronal activity must carry accurate information about the uncertainty of sensory inputs. Two major approaches have been proposed to study neuronal representations of uncertainty. The first one, the Bayesian decoding approach, aims primarily at decoding the posterior probability distribution of the stimulus from population activity using Bayes' rule, and indirectly yields uncertainty estimates as a by-product. The second one, which we call the correlational approach, searches for specific features of neuronal activity (such as tuning-curve width and maximum firing-rate) which correlate with uncertainty. To compare these two approaches, we derived a new normative model of sound source localization by Interaural Time Difference (ITD), that reproduces a wealth of behavioral and neural observations. We found that several features of neuronal activity correlated with uncertainty on average, but none provided an accurate estimate of uncertainty on a trial-by-trial basis, indicating that the correlational approach may not reliably identify which aspects of neuronal responses represent uncertainty. In contrast, the Bayesian decoding approach reveals that the activity pattern of the entire population was required to reconstruct the trial-to-trial posterior distribution with Bayes' rule. These results suggest that uncertainty is unlikely to be represented in a single feature of neuronal activity, and highlight the importance of using a Bayesian decoding approach when exploring the neural basis of uncertainty.


Assuntos
Modelos Neurológicos , Rede Nervosa/fisiologia , Localização de Som/fisiologia , Incerteza , Animais , Vias Auditivas/fisiologia , Teorema de Bayes , Comportamento Animal/fisiologia , Biologia Computacional , Humanos , Colículos Inferiores/fisiologia , Neurônios/fisiologia , Estrigiformes/fisiologia , Colículos Superiores/fisiologia
20.
Environ Sci Technol ; 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35171556

RESUMO

Electric vehicles (EVs) are a promising pathway to providing cleaner personal mobility. China provides substantial supports to increase EV market share. This study provides an extensive analysis of the currently unclear environmental and health benefits of these incentives at the provincial level. EVs in China have modest cradle-to-gate CO2 benefits (on average 29%) compared to conventional internal combustion engine vehicles (ICEVs), but have similar carbon emissions relative to hybrid electric vehicles. Well-to-wheel air pollutant emissions assessment shows that emissions associated with ICEVs are mainly from gasoline production, not the tailpipe, suggesting tighter emissions controls on refineries are needed to combat air pollution problems effectively. By integrating a vehicle fleet model into policy scenario analysis, we quantify the policy impacts associated with the passenger vehicles in the major Chinese provinces: broader EV penetration, especially combined with cleaner power generation, could deliver greater air quality and health benefits, but not necessarily significant climate change mitigation. The total value to society of the climate and mortality benefits in 2030 is found to be comparable to a prior estimate of the EV policy's economic costs.

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